Artificial Human No. 8

A larger-sized construct, No. 8 looked (and was modeled after) the more modern takes on Frankenstein's monster. Despite this, he was actually a very gentle soul. He was deemed a failure due to this fluke in his programming.

When Murasaki learned that he could not defeat Son Goku in Muscle Tower, he activated No. 8 to do his dirty work for him. However, the Artificial Human refused to fight Goku. Murasaki threatened to activate the self-destruct mechanism in No. 8's body, but Goku saved the Artificial Human from being destroyed and the two became friends, taking down Muscle Tower (as well as the Red Ribbon Army near Jingle Village) together. No. 8 still resides there to this day.

Note: Due to Doctor Gero not existing at the time of the manga, a new character, Dr. Flappe, was created to be his inventor. It is generally assumed that in the anime timeline, Dr. Flappe and Doctor Gero worked together back in the days of the Red Ribbon Army.

Artificial Humans No. 9 through No. 15

These and the Artificial Humans who follow were created with the sole intention of killing Goku. However, like 1 through 7, 9 through 12 all had problems which eventually led to them being scrapped. Note: The No. 9 mentioned here should NOT be confused with the Dragon Ball Online character who was the character named Red and revived as a cyborg named No. 9.

In the manga timeline, No. 13, No. 14, and No. 15 were nearly complete, though were not ready enough to be activated (implying that they still needed to be worked on). However, in Super Android 13!, a secret supercomputer continued working where the doctor had left off, eventually releasing the trio out into the public to track down and kill Goku.

Artificial Human No. 13

Artificial Human No. 13 is presumably the most powerful of the three movie-only Artificial Humans. He was able to keep up with Goku in his Super Saiyan form and was eventually defeated, but soon caught his breath and absorbed bits and pieces of his destroyed colleagues to become Super Artificial Human No. 13.

Super Artificial Human No. 13

After absorbing bits and pieces of No.14 and No. 15, the truck driver-styled Artificial Human transformed into a massive blue beast of unbridled power and strength. Nigh-invincible in this form, it took the power of Super Saiyan Goku absorbing a Spirit Bomb to stop him. He is never seen again after his defeat.

Artificial Human No. 14

Built alongside No. 13 and No. 15, Artificial Human No. 14 was a large, powerful, gray-colored Artificial Human. Generally the silent type, he prefered to do his talking with his fists. He was killed by Future Trunks (after becoming a Super Saiyan) and subsequently his remains were absorbed by No. 13. He is never seen again.

Artificial Human No. 15

Artificial Human No. 15 is best described as "a little man in a fancy outfit". His outfit and purple skin gave him the look of a gangster, though he said little more than No. 14. A strange quirk of this Artificial Human was the fact he carried – and drank from – a small alcohol flask kept in his front pocket from time to time. Ultimately, he was destroyed by Super Saiyan Vegeta and absorbed by No. 13. He is never heard from again.

Artificial Human No. 16

Strong and silent, Artificial Human No. 16 stands tall as one of the doctor's largest creations. He shared a gentle nature akin to No. 8, seen staring off into space and admiring nature time and time again. He was programmed to kill Goku, but it is unknown if he would have as the chance to do so never came up in the storyline. This is why he is considered a failure in Dr. Gero's eyes.

His ultimate fate was to play a pivotal role in the defeat of Cell. It was his demise that inspired teenage Son Gohan to release his rage and push to the Super Saiyan 2 form.

Artificial Human No. 17

The Human-like models known as No. 17 and No. 18 are considered too powerful to control.

The male of the twin No. 17 and No. 18, Artificial Human No. 17 looks like your average teenage boy wearing a casual outfit. Unlike all other Artificial Humans before him, he was less a robot and more a cyborg. He and no. 18 were runaways who were abducted and experimented on by Dr. Gero. Because of his rebellious nature, he was considered a failed Artificial Human and sealed away until Dr. Gero, in a fit of desperation, released him and No. 18. Ironically, he ended up killing Dr. Gero. After he and No. 18 finished pummeling the Z Warriors into submission, he, No. 18, and No. 16 wandered off on a long and fun road trip to Goku's house.

Later in the series, No. 17 became little more than fodder for Cell, becoming a part of Cell's very being and powering him up to his Semi-Perfect form. After Cell's defeat, he was revived and continued to wander the countryside, messing with people and having a fun time all by himself.

Artificial Human No. 18

Looks can be deceiving, as this beautiful, young lady can be very dangerous when riled. Much like her twin brother, No. 17, she was too rebellious to control and considered a failed Artificial Human. Also like No. 17, she was a normal, Human girl until Dr. Gero experimented on her. In her first appearance, she humiliated Vegeta (who had just become a Super Saiyan) and helped No. 17 defeat the Z Warriors before she, No. 17, and No. 16 hijacked a Lucky Foods Company van and took a road trip to Goku's house.

Later on, she became absorbed by Cell and helped him achieve his Perfect Form. A few days later, she was spat back out after Cell received an extremely powerful kick to the gut from an enraged Super Saiyan 2 Gohan. After Cell was defeated by Gohan, she wandered off for awhile before returning to the Z Warriors and ultimately marrying Krillin, who had fallen in love with her during the Cell Saga. The two later had a daughter named Marron.

During Dragon Ball GT, she played a much more subdued role, becoming one of Baby's minions during the Baby Saga as well as fighting off Super 17 later on.

Artificial Human No. 19

The energy-absorbing models No. 19 and Doctor Gero himself, as No. 20, are considered successes, but are far weaker than others.

A very strange, round man of an Artificial Human, Artificial Human No. 19 was one of two energy-absorbing models made by Doctor Gero. Despite being destroyed by Super Saiyan Vegeta, he was considered a successful Artificial Human given that he followed his programming to the letter and had enough power to destroy Goku.

During the Dragon Ball GT series, he was seen flying from Hell in the sky and destroying the city. He was later sent back to Hell by Trunks and Son Goten.

Artificial Human No. 20

First shown as an Artificial Human, Artificial Human No. 20 was actually a combination of a robotic body with the brain of Doctor Gero implanted in its head. Much like No. 19, he was an energy-absorbing model and also considered a success by the doctor.

Long before he was an Artificial Human, Doctor Gero was a simple engineer working for the Red Ribbon Army. It was not until Goku single-handedly took down the entire Red Ribbon Army that Doctor Gero focused his attention on motives of pure revenge. As Future Trunks had predicted, two Artificial Humans met the Z Warriors on the battlefield three years after Goku's return to Earth, but unlike Trunks' prediction, it was Doctor Gero himself and No. 19 who met them, rather than No. 17 and No. 18. Ultimately, Doctor Gero was destroyed by No. 17 and wound up in Hell.

Dragon Ball GT introduced us to a new doctor, Mu. After Mu's defeat at the hands of Goku, Trunks, and Pan, Mu and Doctor Gero teamed up to get revenge on them by creating Hell Fighter 17 (and eventually Super 17). After a complicated series of events, Mu and Doctor Gero escaped Hell. Doctor Gero was once again killed by Super 17, much to his surprise.

Cell

The ultimate Artificial Human, Cell was actually a combination of cells extracted from a number of sources (such as the Z Warriors and Freeza and his father). As such, he had the fighting knowledge, power, and even moves of some of the most powerful fighters in the universe. Coming from the future in which No. 17 and No. 18 were already dead, Cell sought to absorb the duo in order to climb to his Perfect form. Oddly enough, he had no intention of taking over the world, but instead sought to destroy it if Goku could not beat him. His present form was destroyed after Trunks and gang destroyed Doctor Gero's Lab and Cell's embryo form.

Ultimately, Cell was defeated by an enraged Gohan and sent to the Next World. He formed a union with Freeza and his Ginyu Force, generally causing havoc and being a pest to the ogres who maintained the peace. Goku (who died in the battle with Cell) was about to stop him, but Pikkon stepped in and promptly put Cell in his place... but only for the time being. After that, the show pretty much showed Cell being in Hell.

Cell once again became a thorn in Goku's side in Dragon Ball GT. Goku, having to go to Hell, ran into Cell and Freeza. However, the two were ultimately defeated and detained by the Ogres of Hell once again by Goku trapping both of them in Hell's ice.

Cell Jr.

While not created by Doctor Gero directly, after reaching his Perfect form, Cell could reproduce asexually through his tail. Taking the shape of child-like, blue Cells, each Cell Junior was almost as powerful as Perfect Cell himself. However, they were far from durable as a single attack from Super Saiyan 2 Gohan was able to destroy each of the seven spawned Cell Junior. These guys kind of resemble the Saibamen in the first season of Dragon Ball Z.

Hell Fighter 17

Created in Hell by Doctor Gero and Mu, Hell Fighter 17 was, aside from being a Machine Mutant, an exact copy of No. 17 and was created to locate, control, and eventually fuse with No. 17 in order to create Super 17.

Super No. 17

Super No. 17

The Fusion of No. 17 and Hell Fighter 17 was a spectacular success, yielding the large and powerful Super 17. With the power of both No. 17 and Hell Fighter 17, he was able to fight and defeat all of the Z Warriors, including Goku, until Goku found his weakness and destroyed him for good. He is never heard from again.

Trivia

Pirate Robot, which Goku, Krillin, and Bulma encounter in the Pirate Cave in "The Trap is Sprung", the 50th episode of the Dragon Ball anime, has the number '2' painted on both of its legs. Since this is apparently the Red Ribbon Army's first venture into the cave and they appear to have no knowledge of the robot, however, it seems highly unlikely that this would be the No. 2 that Doctor Gero had created. Nevertheless, Pirate Robot bares a resemblance to a failed project, possibly No. 3, who hangs strung above what is unarguably the third Artificial Human's laboratory pod in a scene during Future Trunks' telling of Doctor Gero's plot in Dragon Ball Z.

When Cell encounters No. 16, No. 17, and No. 18 on the island that No. 17 and Piccolo were fighting on, Cell implies that older model Artificial Humans often used the Red Ribbon Army insignia displayed.

Interestingly, even though No. 13, No. 14, and No. 15 were not featured in the manga, the "Android A•B•C" section mentions that No. 13, No. 14, and No. 15 were very close to the final Android concept.

Doctor Gero seemed to develop something of a jewelery fetish after the fall of the Red Ribbon Army. No. 16 through No. 19 (as well as No. 13 through No. 15 in Super Android 13!), and even Dr. Gero himself (as No. 20), all wear loop earrings.

In the anime, No. 19 would flick one of his earrings before attacking. No. 13 and No. 17 also did this once against Piccolo. Super 17 does this while searching for Goku once during their fight in Dragon Ball GT as well.